Audiologic tests, such as tympanometry, examines the condition of the middle ear, mobility of the tympanic membrane, and/or the conduction bones by creating variations of pressure in the ear canal. In order to modify the pressure, a probe is inserted into the ear canal creating an air tight seal of the ear canal.
Audiologic tests are conventionally performed by transmitting a continuous tone with a primary component at a primary frequency of 226 Hz towards the tympanic membrane and measuring via a microphone the signal reflected by the tympanic membrane. The choice of 226 Hz is a de facto standard in performing a tympanometry to obtain a tympanogram in adults. In small children a tympanometry is occasionally performed with a tone with a primary component at a primary frequency about 1,000 Hz.
Recent developments within tympanometry include performing a complex and time-consuming test including sequential measurements at many frequencies.
Using a wide-band signal throughout the entire pressure sweep has been proposed. However, such approach leads to superfluous data and reduced signal-to-noise ratio compared to a single-tone signal.
Further, the new approach is not regarded as a standard by authorities, audiologists and other medical personnel.